A curtain wall is an exterior wall for a building which serves only as an enclosure element, as opposed to a structural wall which is essential to the building's structure for purposes of bracing or support. Curtain walls must have sufficient stability and stiffness to resist wind, impact and construction handling, as well as sufficient anchorage to the structural frame, especially against lateral forces.
In order to provide a heating insulating curtain wall for the exterior wall of a building, it is common to use two sheets of glass with an insulating air space therebetween. The glass is typically plain clear window glass which is heat-strengthened.
Curtain walls constructed of glass typically consist of a plurality of vision panels and spandrel panels, mounted side-by-side. Vision panels are panes or portions of the curtain wall through which a person inside the building can see. A spandrel panel is one through which a person cannot see from the interior to the exterior; for example, a spandrel panel could be used to cover the building's floor structure, or mechanical components of the structure.
To achieve a colored effect with conventional curtain wall assemblies, colored or tinted glass is sometimes used for either or both of the glass panels. However, only certain metallic admixtures can be added to glass, so that tinted glass can be produced in only a very limited number of colors. As a result, there are only five available colors of tinted glass: green, blue, bronze, gray and rose.
Another alternative to using tinted glass is to coat a surface of one of the glass panels, usually the inside surface of the outside glass sheet, with an opaque paint or a reflective coating. The paint can be applied in any color, unlike the limited palette for tinted glass. However, the resulting painted glass curtain wall tends to have a flat or shallow appearance.
The present invention addresses these and many other problems associated with currently available curtain walls.